FACTUAL INFORMATION

At approximately 1300 CST, 7 June 1995, a military aircraft suffered a landing gear failure during the landing roll on runway 11 at Darwin. The aircraft ground looped through 180 degrees, coming to rest on the northern (left) side of the runway between taxiways B2 and E2, with about 0.4 m of its left wingtip overhanging the runway.

Not long after that occurrence, the crew of VH-TJV, which was on descent to Darwin, was advised by Air Traffic Control (ATC) of the accident. They were given the location of the disabled aircraft and informed that runway 11/29 would be closed for an estimated period of 1-2 hours. The crew considered using runway 36 but calculations showed that it would be unacceptable. After calculating the aircraft's endurance, the crew decided to divert to Tindal. Both pilots subsequently reported that at the time of the diversion they believed that the accident aircraft was at about the midway point of runway 11/29.

When the aircraft arrived at Tindal the surface movement controller passed a message to the crew from RAAF Darwin, advising that runway 11 now had an available length of 5,500 ft, but with a landing over a displaced threshold and the accident aircraft. Runway 29 was also available with a 15kt downwind component.

RAAF Darwin ATC had advised RAAF Tindal ATC that runway 11 had a landing distance available (LDA) of 1,936 m and a take-off run available (TORA) of 2,036 m. This message was to be passed to the crew of VH-TJV after its arrival at Tindal. The RAAF flight planning officer, who received the message, wrote the LDA and TORA down on a piece of notepad paper and personally delivered it to the aircraft, handing it to the pilot in command. He believed he had advised the pilot in command of the displaced threshold and that the landing would be over the disabled aircraft. The pilot in command remembered being given the handwritten message but stated that he had not been given any information other than the LDA and TORA.

After arranging for the aircraft refuelling and passenger requirements, the pilot in command contacted the company's Operations Department by telephone to report arrival at Tindal, and to arrange for another flight plan to be issued for the Tindal - Darwin sector. A short time later he called Operations again and was transferred to a dispatcher who arranged the flight plan issue. The pilot in command advised that he did not require another copy of the weather as the information he had was still valid. The dispatcher assumed that since the pilot in command was in the area, and aware of the problem in Darwin, there was no need to send the NOTAM concerning the displaced threshold as this would mean transmitting all the Darwin NOTAM pages, therefore only the flight plan was sent.

VH-TJV departed Tindal for Darwin at approximately 1550 CST.

During approach to Darwin the co-pilot obtained the following landing information from the Automatic Terminal

Information Service (ATIS): "Information Juliet, runway 11, displaced threshold, 36, wind 060/10-15, QNH 1009, 29.80, temperature 32, CAVOK, runway 11 LDA 1,936 m, TORA 2,036 m, pedestrians and vehicles operating in the undershoot". The co-pilot annotated the relevant information onto the landing data card, then showed it to the pilot in command who had also been monitoring the ATIS while communicating with ATC. The pilot in command acknowledged but did not confirm the information as required by company policy. Neither pilot could recall noticing the information concerning the displaced threshold.

When the aircraft was on final for runway 11, ATC again advised of the displaced threshold and instructed the crew to report sighting the displaced threshold markers. Then, after a pause of several seconds, the controller advised that the visual approach slope indicator system (VASI) was turned off. The crew subsequently reported that they did not hear the reference to the requirement to sight the markers although they did note that the VASI was not available. ATC did not prompt the crew when they had not reported sighting the displaced threshold markers.

As a precautionary measure when aircraft were landing, all vehicles and personnel were removed from the undershoot area. Only personnel working on the disabled aircraft remained in position.

Although the weather was fine and clear, the crew reported that from the air there was a certain amount of haze and sun glare which made objects on the ground appear to blend into their surroundings  They advised that during the approach they were concentrating on maintaining the correct speed and profile to arrive as close as possible to the threshold in order to utilise all of the available runway length, and did not see the white runway unserviceable crosses located in the undershoot area.

The controllers reported that when they noticed the aircraft on short final, about 150-200 ft above ground level (AGL), it appeared about to land in the undershoot area. The controllers believed that RAAF policy precluded turbo-jet aircraft from going around below 200 ft AGL due to slow engine response time, and therefore considered it safer to allow the aircraft to continue. The crew's first awareness of landing in the undershoot area was when the aircraft passed over one of the white crosses.

The information supplied to the crew by ATC prior to their diversion to Tindal concerning the location of the disabled aircraft, and the available runway length situation, appeared to have allowed both pilots to develop a mindset that the western end of runway 11, that is the normal threshold, was the serviceable area.

The airport operator, who had arranged the displaced threshold, advised that all markings were in accordance with the Rules and Practices for Aerodromes (RPA) standards. The temporarily displaced threshold was marked with Vee-Bars, and the white crosses in the undershoot area were twice the standard size, i.e. 12 m x 0.9 m. RPAs also require runway threshold identification lights (RTIL) to be in place, marking a displaced threshold at aerodromes serving international regular public transport jet aircraft, e.g. Darwin. These lights were not available.

Prior to the occurrence the pilot in command had been rostered for two days on reserve duty, preceded by one day off, and the co-pilot had been off duty for three days. They had completed a 10-hour tour of duty, having flown four sectors including the diversion.

Since 1981 there have been 25 reported occurrences of pilots failing to see runway displaced threshold or unserviceable markings, six occurring since 1990. Anecdotal evidence suggests that this figure may be much higher. In many cases poor contrast of the markings with the surrounding surface may have been the problem.

SIGNIFICANT FACTORS

1. Information flow available for the crew at the Tindal diversion point was inadequate.
2. Information provided to the crew by RAAF Tindal was inadequate.
3. The company flight dispatcher failed to provide a hard copy of the NOTAM to the crew.
4. The Darwin ATIS was misleading; however, enough information was available for the crew to seek clarification.
5. The co-pilot did not take note of the ATIS comments about the displaced threshold, and the pilot in command, contrary to company policy, did not confirm the ATIS information.
6. The crew developed a mindset regarding the serviceable runway and the disabled aircraft location, and did not clarify information available to them.
7. ATC did not verify that the crew understood the instruction to sight the displaced threshold markers.
8. ATC did not issue go-around instructions.
9. Light conditions may have made the runway displaced threshold markings difficult to see.

SAFETY ACTION

The Bureau of Air Safety Investigation issued interim recommendation IR950176 to the Civil Aviation Safety Authority.

"The Bureau of Air Safety Investigation recommends that the Civil Aviation Safety Authority:

"(i) review "runway displaced threshold" and "runway unserviceable" markings to improve the visibility to pilots under all conditions. This review should consider the use of different colours, shapes and backgrounds to increase the contrast and distinguishability of such runway markings; and

"(ii) ensure that airport owners and operators have the correct portable runway lighting available for identifying unserviceable areas of the runway where required."

The following response was received from the Civil Aviation Safety Authority on 17 October 1995:

"I refer to Interim Recommendation IR950176 concerning the displaced threshold incident involving a Boeing 737, VH-TJV, at Darwin on 7 June 1995.

"Summary

"(i) The Authority has no plans to review the standards for runway displaced threshold and runway unserviceable.

"(ii) Work is currently being undertaken on the production of a Civil Aviation Order on Aerodrome Lighting. "Background to Response

"Displaced Threshold and Unserviceability markings depicted in Rules and Practices for Aerodromes, Chapters 11 and 20, are consistent with ICAO standards and recommended practices. The Authority has no plans to review these standards.

"Work is currently being undertaken on the production of a CAO on Aerodrome Lighting which will include the standards for displaced threshold lighting and temporary runway end lighting. It is considered that, in the interim, the requirements of the lighting section of the Rules and Practices for Aerodromes is an adequate and acceptable standard. It is not anticipated that these requirements will be changed significantly with the making of the CAO."

Response status: CLOSED NOT ACCEPTED.

The pilot of VH-LHF was on an instrument flight rules (IFR) flight in instrument meteorological conditions and was conducting an NDB/DME instrument approach procedure for the descent and approach into Moorabbin. When the aircraft was about eight kilometres from the airfield and on the inbound leg of the approach, the Melbourne Radar Advisory Service (RAS) controller observed a radar return from an opposite direction aircraft about four kilometres ahead.

Both aircraft were in uncontrolled airspace. VH-LHF was descending through 1,200 ft and the altitude readout for the other aircraft indicated it was at 1,000 ft. The RAS controller passed traffic information on the unidentified aircraft to the pilot of VH-LHF, who altered heading to turn away from the other aircraft.

The other aircraft was operating under visual flight rules (VFR) procedures and was tracking outbound from Moorabbin, just below the cloud base. There is no instruction to require VFR aircraft to remain clear of the instrument approach track for the Moorabbin NDB approach.  However, written instructions for departures (both VFR and IFR) into uncontrolled airspace include a statement to track clear of VFR approach points.  IFR approach procedures allow appropriately qualified pilots to safely descend in non-visual conditions, and, on occasions, such approaches are used in visual conditions.

Since January 1992 there have been six reported occurrences of VFR aircraft conflicting with regular public transport aircraft making IFR approaches. The problem of possible confliction between IFR aircraft on instrument approaches and VFR aircraft exists at many locations where instrument approach procedures are used outside controlled airspace.

The situation is compounded by the fact that most VFR pilots are not familiar with instrument approach procedures, do not have access to instrument approach charts and are, therefore, usually unaware of the location of instrument approach flight paths.

The existing publications for VFR pilots do not provide information on the locations, directions and altitudes of instrument approach tracks. Overseas, VFR charts show the tracks of IFR approaches. The inbound final instrument approach tracks to Australian aerodromes could be included in a publication to which all VFR pilots have access.

SIGNIFICANT FACTORS

1. There was no information provided to VFR pilots as to the position of instrument approach tracks.
2. There was no statement to require VFR pilots to remain clear of instrument approach flight paths.

SAFETY ACTION

As a result of the investigation, the following interim recommendation was issued to the Civil Aviation Safety Authority (CASA) and Air Services Australia:

IR950206

The Bureau of Air Safety Investigation recommends that the Civil Aviation Safety Authority:

1. publish details of final inbound instrument approach paths at aerodromes in a format to assist VFR pilots in avoiding these areas; and,
2. highlight to VFR pilots the need for caution and vigilance when operating in the vicinity of the final instrument approach legs at aerodromes containing a published instrument approach.

The following response was received from the Civil Aviation Safety Authority on 11 September 1996:

"I refer to your interim recommendation IR950206 concerning the incident involving PA31-350, VH-LHF, and PA34-200, VH-PCP at Moorabbin on 3 June 1995. The following comments are forwarded for your consideration.

To be practically utilised in flight by VFR pilots, details of the final track of instrument approaches need to be depicted on a navigational chart. Current navigation charts are either not able to accommodate the inclusion of this information or, in the case of VTC, there is insufficient coverage. However, as part of the Airservices/Defence joint charting program, work is progressing in evaluating the production of a 1:500,000 visual navigation chart (VNC) which could be a suitable chart for provision of the information."

The following response was received from Air Services Australia on 29 August 1996:

"With regard to the publication of instrument approaches on charts to assist VFR pilots, as discussed in IR950206, I understand that CASA is in the process of reviewing this recommendation. In addition, publication of instrument approaches on charts is currently under discussion in the Airspace 2000 proposals on pages 36 and 68 of the document titled "Airspace 2000 - A Plan for the Future of Australian Airspace"."

Response Status - OPEN

The pilot reported that, on approaching top of descent, the flight attendants noticed smoke coming from the rear toilet.

Investigation revealed a small fire in the rear toilet waste bin. The fire was extinguished by crew using water and BCF fire extinguishers. A normal approach and landing was carried out at Maroochydore.

Passengers were subsequently interviewed by Queensland Police but neither the cause of the fire nor the person responsible could not be identified.

The burnt material appeared to be a small quantity of rolled up tissue paper.

The pilot was faced with a forced landing when he inadvertently left the fuel selector on a near empty (left wing) tank. The purpose of the flight had been to inspect a property and when the engine faltered, due to fuel starvation, there was insufficient time and height available to restart the engine using fuel from the right tank.

The aircraft struck a beast, with the left main gear, during the flare. The gear leg was bent back and during a short landing roll, the left wing struck the ground.

The flight was intended as a brief pleasure/practise flight in the local area in an aircraft borrowed from a friend.  The pilot had only 90 minutes previous flying experience in the aircraft while sitting in the right front seat with the owner/friend acting as pilot-in-command in the left seat.  However, the pilot had flown several hours as pilot-in-command of a Debonair, which is similar, and advised that his friend had pointed out the differences between the Bonanza and the Debonair.  The accident flight lasted only 30 minutes and was the first time the pilot had acted as pilot-in-command of a Bonanza.

The pilot advised that, as part of the preflight inspection, he had visually checked the contents of both main fuel tanks and assessed that there was enough fuel on board for a short flight.  He did not dip the tanks.  He started the engine on the left main tank and maintained that selection in flight until the engine lost power on final approach for runway 35 at Tyabb.  He then changed the fuel selector to the right main tank.  The engine did not regain power. The aircraft touched down on its wheels in an open paddock about 400 metres short of runway 35 threshold.  During the landing roll the aircraft ran through a farm fence before coming to rest about 200 metres short of the threshold.

An inspection and tests conducted after the accident confirmed that the engine had failed due to fuel starvation.  The fuel gauges read zero.  No fuel leaks were found.  Both main fuel tank floats were resting on their static low stops, namely the bottom of the rubber fuel cells. After the aircraft was recovered, the engine was started and ran normally after air was purged from the fuel lines.  When asked about the low fuel gauge readings at the commencement of the flight, the pilot said that he did not take too much notice of them because he had visually assessed the fuel level as adequate for the flight and that flying instructors in the past had told him that fuel gauges could not be believed because they were notoriously inaccurate in light aircraft.

Total engine time for the flight was about 35 minutes.  When both main tanks were drained after the accident, one third of a litre of AVGAS drained from the left main tank and eight litres from the right main tank.  Both of the auxiliary fuel tanks were empty.  The approved flight manual lists the unusable fuel in both main tanks combined as 22.7 litres (i.e. 11.35 litres per main tank).  The flight manual also states, "Do not take-off if fuel quantity gauges indicate in yellow band or with less than 11 Imperial or 13 U.S. gallons in each main tank" (i.e. 49 to 50 litres in each main tank).  The pilot said he did not recall this comment in the flight manual.

Pilots experienced in this model Bonanza advised that it uses about 42 to 45 litres of AVGAS per hour.  VH-AYU's engine somehow managed to use about 11 litres of the unusable fuel from the left main tank before it lost power.

When the pilot selected the right tank, its fuel level was already within the unusable fuel range; it contained only about 9 litres.  There was probably insufficient time and insufficient fuel in the right main tank to achieve adequate fuel flow/pressure to restart the engine before the aircraft touched down in the paddock.

Significant factors

The following factors were considered relevant to the development of the accident:

1. The pilot's visual assessment of the fuel quantity within both main tanks was incorrect.
2. The pilot ignored the fuel gauge readings.
3. The pilot's knowledge of the flight manual content was inadequate.
4. The engine failed due to fuel starvation.

The pilot was conducting a familiarisation flight in the local area. After conducting a series of circuits and landings, he departed on a short cross-country flight. Shortly after levelling off in the cruise at about 2200 ft AGL, the pilot heard a muffled bang, followed by a severe shudder through the airframe. The engine then stopped. The pilot immediately transmitted a Mayday call and then proceeded to conduct a forced landing on to a newly ploughed field. During the landing roll, the nose wheel broke through the loose soft surface and the aircraft nosed over.

The pilot was able to exit the aircraft unaided, suffering only minor injuries to his neck and back.

Later examination of the engine found that the engine crankshaft had failed.

FACTUAL INFORMATION

The Boeing 737 had landed on runway 35 and commenced taxiing back to the terminal.  There was a requirement to cross that runway again in order to reach the terminal. After being instructed to hold short of runway 35, the crew were subsequently given a clearance to cross and to hold short of runway 30.  The crew replied to this instruction with the aircraft callsign only, consistent with the requirements of AIP OPS CTL paragraph 15.1 to 15.3 and OPS CTL paragraph 25 - note 1 and 3.

At this time, the crew turned on the navigation and landing lights in accordance with their company Standard Operating Procedures (SOPS) and crossed runway 35.

A Cessna 152 was on final approach for runway 30 and was cleared for a touch-and-go.

After crossing runway 35, the crew of the Boeing confirmed between themselves that they were cleared to cross runway 30 and, in doing so, left the navigation and landing lights on as they proceeded to cross this runway.

Before entering the runway strip, they checked both approaches.  The co-pilot looked to the right while the pilot in command looked to the left, the direction from which the Cessna was approaching.  At this time, the Cessna was in the final stage of its approach.  The pilot-in-command did not see the Cessna. As the two aircraft were transmitting on different frequencies, the crew of the Boeing did not hear the landing clearance given to the pilot of the Cessna.

As the Cessna was touching down the Surface Movement Controller (SMC) and the Aerodrome Controller (ADC) observed the Boeing infringe the flight strip of runway 30.  The crew of the Boeing were instructed to hold position by the SMC while the ADC instructed the pilot of the Cessna to stop immediately.

The Cessna stopped at the intersection of runway 35 and 30. The Boeing stopped within the flight strip of runway 30.  The distance between the two aircraft was 525 metres.  The crew of the Boeing were then cleared to cross runway 30, after which, the pilot of the Cessna was given a clearance to take off.

Analysis of the Automatic Voice Recorder (AVR) tape confirmed that the SMC had, in fact, issued the instruction to hold short of runway 30. The tape also indicates that, at the same time the instruction was given to hold short of runway 30, there was a transmission from another station which was not discernible. The over-transmission made it difficult to clearly hear this part of the clearance. The crew of the Boeing were sure, however, that they heard a clearance to cross both runways.  It has been common in the past for such a clearance to be given at Canberra.

The weather at the time of the incident, as described by the Automatic Terminal Information Service (ATIS), indicated light and variable winds with a visibility of more than 10 kms in haze.

ANALYSIS

As it was not uncommon to receive a clearance to cross both runways at Canberra, the crew of the Boeing appeared to have the expectation of such a clearance in this incident.  Even though the transmission from another station may have made it difficult for the Boeing crew to clearly hear the instruction to hold short of runway 30, this expectation appears to have overridden any possible ambiguity the crew may have had about the clearance instruction.  As the crew were sure they had heard the instruction to cross both runways, it was not necessary for them to clarify these instructions.

The acknowledgement of the clearance instruction with the aircraft callsign indicated an understanding of that instruction. ATC would not, therefore, have been alerted to the misunderstanding.

At the time the pilot-in-command scanned the final approach area to runway 30, shortly before the Boeing commenced crossing that runway, the Cessna may have been difficult to sight. At that time, it is likely that the Cessna was below the line of hills to the south-east of the aerodrome.  The haze that existed at the time of the incident would have affected the visibility and may have increased the difficulty in sighting the Cessna.

CONCLUSIONS

Findings

1. The SMC issued the Boeing with a clearance instruction to cross runway 35 but to hold short of runway 30.
2. The instruction to hold short of runway 30 was over transmitted by another station.
3. The crew did not check or confirm the unclear instruction.
4. The crew acknowledged the instruction with the aircraft callsign only.  Such an acknowledgement indicated to SMC that the crew understood the instruction to hold short of runway 30.
5. As the crew of the Boeing was transmitting on a different frequency to the pilot of the Cessna, they did not hear the landing clearance that was given to the Cessna.
6. The pilot in command did not see the Cessna on its final approach to runway 30.

Significant Factors

1. The crew appeared to have had an expectation to be issued with a clearance instruction to cross both runways.
2. The acknowledgement of the instruction with the callsign only did not alert ATC to the misunderstanding.
3. The Cessna may have been difficult to see on its approach path due to a line of hills to the south-east of the aerodrome.
4. The visibility at the time of the incident was affected by haze.

The aircraft was spraying thistles when the accident occurred. There were several areas to be treated on the property. The first area had been completed, and the pilot was flying the first swarth run on the next area when the aircraft hit a double wire powerline which culminated in a severe impact with the ground.

The investigation revealed that the pilot had been given a map of the property by the property owner. The map had two powerlines depicted but did not show the powerline that the aircraft hit. The span was reported to be about 450 metres, and the poles were remote from the point of impact. Prior to commencement of spraying the pilot made an aerial inspection of the area for powerlines and other hazards. He did not identify the powerline that the property owner had neglected to mark on the map.

Significant Factors

The following factors were considered relevant to the development of the accident:

1. The pilot was not made aware of the existence of the powerline that he hit, and he did not see it during his aerial inspection of the property before commencement of spraying.

2. The span of powerline that the aircraft hit was about 450 metres and the poles were remote from the impact point, thus denying the pilot cues as to its existence.

The pilot stated that, when the aircraft was about 900 ft above the ground on approach to the runway, the engine began to lose power. She then commenced engine failure checks. The electric fuel pump was turned on, the throttle, pitch and mixture levers were moved fully forward and the circuit breakers, master switch and magnetos were checked. As there was no response from the engine the pilot then changed from the right to left fuel tank, then subsequently back to the right. The engine still did not respond, and a forced landing was made in a cane field.

All six occupants evacuated the aircraft and were not injured.

The pilot later said that the left fuel gauge read one quarter, and the right gauge read three quarters full.

Post flight inspection found the left fuel tank empty, but the right tank had sufficient fuel for continued flight. The inspection also determined that both fuel tank gauges were misreading and that no fuel calibration card was available in the aircraft.

The pilot's management of the fuel system was not in accordance with the Aircraft's Pilot's Operating Manual which indicates that the fuel should be managed in such a way as to balance the aircraft laterally or handling/trim penalties would result. However, the pilot operated from the left tank for almost the entire flight. There had been approximately two hours of fuel in each tank at the commencement of the flight with a flight plan indicating a requirement for a little under two hours of fuel.

Correct operating procedures for changing tanks also require the change to be made at the selector before the electric fuel boost pump is switched on, in order to prevent air entering the fuel line to the engine. It is probably a co-incidence that the switching took place as air from the empty left tank entered the line. This would have had the effect of totally confusing the pilot who diagnosed a fault with the half full right tank and switched back to the empty left tank. Once the fuel feed line to the engine contains air, it takes a considerable time for it to be purged by fuel under pressure from the electric boost pump. The pilot did not have this time available when the engine lost power at 900ft altitude.

The sector 12 controller was responsible for ensuring separation was maintained between the two aircraft. ZK-NZY was tracking direct from over Sydney to Melbourne and this track took it close to over Canberra. VH-EWI was proceeding via over Cooma and Canberra to Sydney. Both were cruising at flight level 280. It was necessary to retain either 1000 feet of vertical separation or five miles horizontal separation.

The controller considered the option of vectoring in the vicinity of Canberra to ensure separation was maintained. However, she assessed that the lateral separation of five miles would be retained without the need for this. In spite of this assessment the horizontal distance between the two aircraft reduced to 4.5 miles.

Significant Factors

The following factors were considered relevant to the development of the incident:

1 The controller did not take positive action to ensure that the minimum required separation was maintained.